Honestly, unless you truly have massive, speed-demon internet speeds, internet backup for photos is a non-starter, if you shoot any volume of images. A week's shoot for me averages 130-160GB. I can't think of a ISP/bandwidth out there that would either provide a quick backup or not hammer you for "excess use" with volume like that. Even my "portfolio" image folder is over 25GB.

I am currently using xdrive’s free account for storing few precious photos apart from generating backups on a spare hdd and DVDs. Another alternative you can probably look at is BQBackup, they have a good reputation amongst webmasters for backing up server data and thus offer ftp access.